[MF3D.FORUM:1077] Skies and Clouds (was Re: [blank])

[Paul Talbot <ptww@xxxxxxxxx>]

Bill Glickman wrote:

> In such cases like extremely overcast days, you get perfectly 
> exposed subjects with no shadows, excellent!  However, the sky
> holds way too much light when overcast and the chrome will become
> clear acetate in the sky area.  This looks a bit awkward in the
> viewer of course...but the subjects look GREAT.

Yes, I try to avoid including light overcast skies in the scene
whenever possible.  Of course that's not always possible, and it
is especially hard with a wide base MF twin rig where you are
trying to keep the near ground out of the picture also.

> So I realize it would be hard to put in clouds and a sky in Photoshop
> since you have to get that stereo placement right for the clouds.

Unless the stereo base is very large, there will be little to no
binocular disparity between the clouds and the sky.  Certainly
there would be none between the highest clouds (sirrus?) and the
sky.  I presume, though, that you would want to add nice low puffy
cumulus clouds.

> And that must be very hard,

I don't use Photoshop yet, but the binocular disparity would be so
slight, that I would guess you could just shift the clouds a couple
pixels to give the appearance of them being stereoscopically in
front of the sky.  If you wanted to create the appearance of full
roundness within the clouds, it would become more time consuming.
But I'm guessing that would not be needed for most shots.

> But, it seems just throwing in
> a solid blue sky maybe with a bit of graduation would fuse perfectly and
> seem totaly real.  

It should work very well.  Mark Dottle (photo-3d) uses "film gels" to
add blue color to washed out skies.  It works, though the realism is
sometimes lacking because without the help of computer manipulation
it is not practical to match the shape of the added color to the
shape of the skyline.  George T co-wrote an article with Mark about
the film gel technique, but I've forgotten where it was published.

> So has anyone attempted to scan some of these type shots
> fix them up and reprint them either in a film recorder (digital printer that
> prints to film) or on Trans paper in a home type printer?

Bill, you may be the only person on the list who has access to that
kind of equipment!  Most of us will have to rely on experiencing it
vicariously through your follow up reports!  ;-)

Paul Talbot